John Downer, Senior Lecturer in Risk and Resilience at the University of Bristol's School of Sociology, Politics, and International Studies, describes the parallels between the civil aviation and civil nuclear sectors. His research explores science, risk, and governance, with a focus on complex technological infrastructures, like nuclear power, and the nuances within the "techno-politics" of environmental discourse, like radiological pollution.

In this presentation, John draws parallels between civil aviation and civil nuclear industries. Both domains operate as complex socio-technical systems that demand active maintenance to ensure safety. A common requirement they share is ultra-high reliability—a standard defined as a mean time to catastrophic failure of over a billion hours of operation.

Learning from each other's regulatory approaches, civil aviation and nuclear industries incorporated analogous frameworks in their processes. When nuclear regulations leaned towards quantification, aviation regulations followed a similar path. Both sectors rely on common documents and deeply entrenched methodologies to manage ultra-high reliability. Regulatory agencies such as the NRC and FAA in the United States evaluate and endorse new reactor and jetliner designs through comprehensive procedures. The amalgamation of test results via theoretical models, including redundancy calculations, cements the reliability of the systems, eliminating doubts from future discussions.

John's intrigue in this subject originates from his background in the philosophy of science. He's fascinated by the logical challenges within scientific methodologies, particularly the elusive certainty when tests or theoretical models attempt to represent the complexities of the real world.

Notably, the aviation sector has tangibly achieved the level of reliability claimed, substantiated by extensive operational data from thousands of jetliners. Unlike reactors, jetliners boast statistical evidence supporting their reliability claims, a testament to their operational success. Exploring how these airframes navigate epistemological challenges without compromising their reliability claims has been a focal point of John's research.

To achieve high reliability standards in civil aviation, extensive service experience, rigorous investigation of failures, and a cautious, incremental approach to design changes have become the norm. The implications for the nuclear industry suggest the potential of similar reliability if a common reactor design paradigm were embraced, built, and refined over time. Unlike aviation, the nuclear sector lacks unified service experience and design stability, which presents challenges in achieving comparable reliability.

The differences in how these industries gain experience, coupled with the extended service life of nuclear reactors, gives rise to considerations for accelerated aging protocols, like seen in fields like the navy.

John’s presentation shows the complexities within these sectors, which helps us to reflect on safety, reliability, and the challenges in managing high-risk, high-stakes technological systems.